食品科学 ›› 2018, Vol. 39 ›› Issue (24): 78-84.doi: 10.7506/spkx1002-6630-201824013

• 生物工程 • 上一篇    下一篇

一种米曲霉耐盐蛋白酶的纯化及酶学性质分析

毛丙永1,刘艳凤1,赵国忠2,崔树茂1,赵建新1,*   

  1. (1.江南大学食品学院,江苏?无锡 214122;2.天津科技大学食品工程与生物技术学院,天津 300457)
  • 出版日期:2018-12-25 发布日期:2018-12-17
  • 基金资助:
    国家自然科学基金青年科学基金项目(31401682);国家自然科学基金面上项目(31471721)

Purification and Characterization of a Salt-Tolerant Protease from Aspergillus oryzae 3.042

MAO Bingyong1, LIU Yanfeng1, ZHAO Guozhong2, CUI Shumao1, ZHAO Jianxin1,*   

  1. (1. School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; 2. College of Food Engineering and Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China)
  • Online:2018-12-25 Published:2018-12-17

摘要: 采用硫酸铵沉淀、Q-HP阴离子交换柱和Superdux 75凝胶柱等技术,从酱油大曲中纯化得到一种耐盐蛋白酶,经飞行时间质谱鉴定为钙蛋白酶RIM13,属于一种半胱氨酸蛋白酶。该蛋白酶的最适温度为50?℃;最适pH值为6.5;稳定温度为40?℃;稳定pH值为7.0;Mn2+促进蛋白酶活力,Fe3+、Fe2+、Cu2+、Ca2+、K+、Na+抑制蛋白酶活力,以上金属离子对蛋白酶二级结构也产生不同程度的影响;米氏常数Km为2.43?g/L,最大反应速率Vm为103.09?mg/(L·min)。在5、10?g/100?mL和15?g/100?mL的NaCl质量浓度条件下,蛋白酶保留的酶活力分别为77.22%、54.39%以及41.15%。该蛋白酶在高盐度环境下保持较高的酶活力,因此具有潜在的工业应用价值。

关键词: 米曲霉, 蛋白酶, 纯化, 酶学性质?

Abstract: In this study, protease was purified consecutively by ammonium sulfate precipitation, Q-HP anion-exchange chromatography and Superdux 75 gel chromatography. Matrix-assisted laser desorption/ionization-time of flight/time of flight (MALDI-TOF/TOF) mass spectrometry analysis suggested that the protease was highly similar to calpain RIM13, a cysteine protease from Aspergillus oryzae. The optimal temperature was 50 ℃ and the optimal pH was 6.5. The enzyme was stable at 40 ℃ and pH 7.0. It was activated by Mn2+, but inhibited by Fe3+, Fe2+, Cu2+, Ca2+, K+ and Na+. The metal ions affected its secondary structure. The Km and Vm values of the protease for casein were 2.43 g/L and 103.09 mg/(L·min), respectively. At NaCl concentrations of 5, 10 and 15 g/100 mL, the protease retained 77.22%, 54.39% and 41.15% of its initial activity, respectively. Consequently, the protease has potential industrial applications.

Key words: Aspergillus oryzae, protease, purification, enzymatic properties

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